linux/net
Eric Dumazet 564824b0c5 net: allocate skbs on local node
commit b30973f877 (node-aware skb allocation) spread a wrong habit of
allocating net drivers skbs on a given memory node : The one closest to
the NIC hardware. This is wrong because as soon as we try to scale
network stack, we need to use many cpus to handle traffic and hit
slub/slab management on cross-node allocations/frees when these cpus
have to alloc/free skbs bound to a central node.

skb allocated in RX path are ephemeral, they have a very short
lifetime : Extra cost to maintain NUMA affinity is too expensive. What
appeared as a nice idea four years ago is in fact a bad one.

In 2010, NIC hardwares are multiqueue, or we use RPS to spread the load,
and two 10Gb NIC might deliver more than 28 million packets per second,
needing all the available cpus.

Cost of cross-node handling in network and vm stacks outperforms the
small benefit hardware had when doing its DMA transfert in its 'local'
memory node at RX time. Even trying to differentiate the two allocations
done for one skb (the sk_buff on local node, the data part on NIC
hardware node) is not enough to bring good performance.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-16 11:13:19 -07:00
..
9p Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-06 19:39:31 -07:00
802 net: return operator cleanup 2010-09-23 14:33:39 -07:00
8021q net: add a core netdev->rx_dropped counter 2010-10-05 14:47:55 -07:00
appletalk Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-04-11 14:53:53 -07:00
atm Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-11 12:30:34 -07:00
ax25 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-09 22:27:33 -07:00
bluetooth Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-11 12:30:34 -07:00
bridge net dst: use a percpu_counter to track entries 2010-10-11 13:06:53 -07:00
caif Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-06 19:39:31 -07:00
can net: simplify flags for tx timestamping 2010-08-19 00:08:30 -07:00
core net: allocate skbs on local node 2010-10-16 11:13:19 -07:00
dcb include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
dccp dccp: cosmetics - warning format 2010-10-12 06:57:43 +02:00
decnet net dst: use a percpu_counter to track entries 2010-10-11 13:06:53 -07:00
dns_resolver DNS: If the DNS server returns an error, allow that to be cached [ver #2] 2010-08-11 17:11:28 +00:00
dsa phylib: available for any speed ethernet 2010-08-11 23:03:50 -07:00
econet net: return operator cleanup 2010-09-23 14:33:39 -07:00
ethernet net: return operator cleanup 2010-09-23 14:33:39 -07:00
ieee802154 ieee802154: Fix possible NULL pointer dereference in wpan_phy_alloc 2010-05-23 23:11:07 -07:00
ipv4 net dst: use a percpu_counter to track entries 2010-10-11 13:06:53 -07:00
ipv6 net dst: use a percpu_counter to track entries 2010-10-11 13:06:53 -07:00
ipx include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
irda irda: Fix heap memory corruption in iriap.c 2010-10-11 02:12:26 +02:00
iucv net: use __packed annotation 2010-06-03 03:21:52 -07:00
key net: return operator cleanup 2010-09-23 14:33:39 -07:00
l2tp net: constify some ppp/pptp structs 2010-09-21 18:04:47 -07:00
lapb include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
llc net/llc: storing negative error codes in unsigned short 2010-09-16 22:38:23 -07:00
mac80211 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2010-10-08 15:39:28 -04:00
netfilter ipvs: Use frag walker helper in SCTP proto support. 2010-10-05 00:27:05 -07:00
netlabel net: Remove unnecessary returns from void function()s 2010-05-17 23:23:14 -07:00
netlink Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2010-10-08 15:39:28 -04:00
netrom net: sk_sleep() helper 2010-04-20 16:37:13 -07:00
packet net: simplify flags for tx timestamping 2010-08-19 00:08:30 -07:00
phonet Phonet: 'connect' socket implementation for Pipe controller 2010-10-13 14:40:34 -07:00
rds Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-27 01:03:03 -07:00
rfkill net: return operator cleanup 2010-09-23 14:33:39 -07:00
rose Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-27 01:03:03 -07:00
rxrpc Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
sched neigh: Protect neigh->ha[] with a seqlock 2010-10-11 12:54:04 -07:00
sctp Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-04 11:56:38 -07:00
sunrpc Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-06 19:39:31 -07:00
tipc tipc: clean out all instances of #if 0'd unused code 2010-10-13 14:27:34 -07:00
unix AF_UNIX: Implement SO_TIMESTAMP and SO_TIMETAMPNS on Unix sockets 2010-10-05 14:54:36 -07:00
wanrouter net: autoconvert trivial BKL users to private mutex 2010-07-12 20:21:47 -07:00
wimax Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2010-05-20 21:04:44 -07:00
wireless Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2010-10-08 15:39:28 -04:00
x25 X.25 remove bkl in poll 2010-09-22 13:35:51 -07:00
xfrm xfrm: Allow different selector family in temporary state 2010-09-20 11:11:38 -07:00
compat.c From abbffa2aa9bd6f8df16d0d0a102af677510d8b9a Mon Sep 17 00:00:00 2001 2010-06-03 20:03:40 -07:00
Kconfig net: RPS needs to depend upon USE_GENERIC_SMP_HELPERS 2010-09-14 21:42:22 -07:00
Makefile DNS: Separate out CIFS DNS Resolver code 2010-08-05 17:17:51 +00:00
nonet.c
socket.c net: remove address space warnings in net/socket.c 2010-09-08 13:46:13 -07:00
sysctl_net.c net: Remove unnecessary returns from void function()s 2010-05-17 23:23:14 -07:00
TUNABLE